Basically:

A woman divorces her husband.

Her husband is a multi-millionaire who owns a football (soccer) team in the UK. The woman gets to keep the team as part of the divorce settlement and since it's the one thing he truly loved, decides to destroy it.

To do so she hires a new Head Coach, Ted Lasso, who's a small time Football (as in American Football) coach from the US who has absolutely no clue about how Soccer works.

But it turns out he's basically like all the feel good coaches you see in movies. He's very good at his job and is super likeable.

The show in general is just really funny and very feel-good.
Ted is just stupidly lovable.